The invention relates to an airbag module.
Known airbag modules comprise a gas generator that is mounted in the module by means of at least one elastic element so as to be uncoupled in terms of vibration.
So far, such airbag modules are exclusively provided in steering wheels and they offer the advantage that the relatively heavy gas generator is mounted so as to be uncoupled from the rest of the module in terms of vibration, as a result of which the tendency of the steering wheel to vibrate decreases. The gas generator can also be configured as a so-called vibration absorber. The uncoupling of the gas generator is achieved by means of the elastic element(s) with which the gas generator is held in the module. The elastic element has to meet high demands, for example, it has to be as uniformly elastic as possible over the operating temperature range of xe2x88x9240xc2x0 C. to +80xc2x0 C. and it also has to be aging-resistant. Moreover, the attachment to the gas generator has to be very secure, with, for example, vulcanization being conceivable.
The invention provides an airbag module with a simply structured elastic element that meets the above-mentioned requirements.
This is achieved in an airbag module which comprises a holding part and a gas generator that is mounted to the holding part by means of at least one elastic element. The elastic element is a hollow profile closed as seen in cross-section and has a circumferential wall a radial outer side of which lies against the gas generator on the one hand, and against a holding part on a module side on the other hand. A hollow profile has the advantage that, due to its geometry, it adapts very well to contours since it can also yield considerably inwards as compared with a solid O-ring or a rubber pad, as a result of which its elasticity can be increased.
Preferably, the elastic element completely surrounds the gas generator, and moreover, it can seal off a gap between a holding part on the module and the gas generator, so that the elastic element has a double function (uncoupled mounting on the holding part and sealing). The seal serves to ensure that no gas can escape from the module in the area of the holder of the gas generator.
According to a preferred embodiment, the elastic element has the shape of a circumferentially closed ring, which increases the tightness.
On its inside, the elastic element can also be foam-filled in order for its stability to be increased. However, an increase in stability can also be achieved in that at least one elastic support element is incorporated into the elastic element. This support element is preferably inserted into the elastic element (for example, during its production) or into openings in the elastic element.
One embodiment makes provision that the elastic element assumes a circular cross-section in the non-installed state, that is to say, it is a hollow profile that is very simple to make.
A first embodiment of the invention proposes that the gas generator has a radial holding flange comprising upper and lower sides, with one elastic element each lying against the upper and lower sides, respectively. Holding parts are provided by means of which the elements are pressed towards each other, in order to clamp the holding flange between them. An advantage here is the simple assembly and the easy manufacture of the elastic elements.
A second embodiment makes provision that there is only one single elastic element, it extending from the upper side of the holding flange of the gas generator and along the circumferential edge as far as to the lower side of the holding flange. Holding parts are provided by means of which the elastic element is pressed against the upper and lower sides, in order to clamp the holding flange between them. The main advantage of this embodiment is that only one single elastic element is provided, which also extends radially outside of the circumferential edge.
Preferably, one of the holding parts that effectuate the clamping of the elastic element is a pot-shaped diffuser that surrounds the gas generator, in other words, a part that is provided anyway and that, with the clamping of the elastic element or elements, acquires an additional function.
In the airbag module according to the invention, the hollow profile is stressed by the gas generator perpendicular to its lengthwise extension, that is to say, as seen in the cross-section, perpendicular to its lengthwise extension. In the state of the art, there are elastic elements in the form of short bushings but these bushings are stressed in the axial direction so that their resilience is limited. Moreover, these bushings only constitute punctual supports and cannot provide a sealing function.